.hc-ad {
    position: relative;
}

.close {
    position: absolute;
    top: 0;
    right: 0;
    cursor: pointer;
    width: 20px;
    height: 20px;
    line-height: 20px;
    text-align: center;
    background-color: rgba(255, 255, 255, .6);
    border-radius: 50%;
}

.close:hover {
    background-color: rgba(255, 255, 255, 1);
    color: red;
}